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Work with multi layers coating films and method of forming multi layers coating filmsRelated Patent Categories: Stock Material Or Miscellaneous Articles, Composite (nonstructural Laminate)Work with multi layers coating films and method of forming multi layers coating films description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070065668, Work with multi layers coating films and method of forming multi layers coating films. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This application claims foreign priority from Japanese Patent Application Nos. 2005-275893, filed on Sep. 22, 2005, and 2006-221516, filed on Aug. 15, 2006, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a work such as metallic member to be coated with coating films and a method of forming coating films on a work to be coated. More in particular, it relates to a work formed with coating films on a metallic member of a braking member used, for example, in industrial machines, railway vehicles, cargo vehicles, passenger cars, etc. and a method of forming the coating films on the work. More specifically, it relates to a work such as a metallic member to be formed with coating films and a method of forming the coating films on the work, in a friction member used in the applications described above. [0004] 2. Related Art [0005] Conventionally, in order to improve a corrosion resistance and a weather resistance, it is widely used to form a coating film on a metallic member. As a method of forming the coating film, various methods including a spray coating, an immersion coating, an electrophoretic coating, a powder coating, and so on are known. In the methods, methods for using coating compositions including a solvent require a step of recovering the solvent. However, since the step of recovering the solvent has problems such as safety, the methods for using coating compositions including the solvent are going to be changed to another methods. In the methods, since the powder coating does not use the solvent, needs simple steps, and is able to recover powder which is not coated in a coating step, the powder coating has a merit such as a cost reducing. However, a continuous coating film is formed by welding powder particles to each other by heating and baking, after a coating layer is formed by adhering powder bodies on a surface of a metallic member. Therefore, it is difficult to obtain a complete covering coating film. [0006] For example, in a powder coating of a friction member (brake pad), a powder coating material of an epoxy resin or epoxy-polyester resin type has been used so far, for example, as disclosed in JP-A-2004-27035. However, this involves a problem that corrosion resistance and close adhesion are not sufficient and this is not sufficient also for the noise characteristic caused from the friction member (brake pad) as a source of vibrations in view of the poor flexibility and damping characteristic. Referring to the corrosion resistance, aside from the corrosion resistance of the bonding surface per se, there is a possibility in the market that adhesion peeling due to rust at the bonding surface when a water content intruding from a dove-tail groove of the friction member (binding hole for molding) the lateral surface of a friction member reaches the bonding surface, or adhesion peeling due to growing of rust generated at the periphery of the bonded portion for the friction member where the friction material is not present and intrusion thereof to the bonding surface, and a countermeasure in districts suffering from salt damages such as North American Area results in a significant problem in the future. [0007] It is an object of the present invention to provide a work to be coated such as a metallic member and a method of forming a coating film of the work for a coating film with an excellent corrosion resistance and a weather resistance, in which a film that elastomer particles is dispersing is obtained by a powder coating. SUMMARY OF THE INVENTION [0008] In accordance with one or more embodiments of the present invention, a work to be coated with multi layers of coating films is provided with: a first layer of coating film formed by coating a powder coating material of a thermosetting resin containing an electroconductive filler and an elastomer on a surface to be coated on the work; a second layer of coating film formed by coating a powder coating material of a thermosetting resin containing water repellent particles on the first layer of coating film, wherein the first layer of coating film and the second layer of coating film are baked by heating. [0009] Further, the work may be a friction member comprising a metal pressure plate and a friction material. [0010] In accordance with one or more embodiments of the present invention, a method of forming multi layers of coating films on a work to be coated, the method is provided with the steps of: forming a first layer of coating film by coating a powder coating material of a thermosetting resin containing an electroconductive filler and an elastomer on a surface to be coated on the work; forming a second layer of coating film by coating a powder coating material of a thermosetting resin containing water repellent particles on the first layer of coating film; and baking the first layer of coating film and the second layer of coating film by heating. [0011] Further, the step of forming the first layer of coating film may be conducted by electrostatic coating on the surface of the work by using an epoxy resin type powder coating material containing particles of one or more of metals such as aluminum and zinc, carbon black, and particles of metal oxides such as zinc oxide and titanium oxide as the filler. [0012] Further, the step of forming the second layer of coating film may be conducted by electrostatic coating on the first layer of the coating film by using an epoxy resin type powder coating material containing one or more of polytetrafluoroethylene and polytrifluoroethylene as the water repellent particles. [0013] According to the method of forming multi layers of coating films on a work to be coated and the work of one or more embodiments of the present invention, in which the first layer of coating film comprising an electroconductive filler and elastomer particles dispersed therein and the second layer of coating film comprising water repellent resins dispersed therein, a coated work excellent in the close adhesion of the coating film, corrosion resistance, weather resistance and vibration proofness of a coated film can be produced and adhesion peeling caused by rust during use can be prevented. When a metallic pressure plate of a braking member in which a friction member is adhered to the metallic pressure plate is provided with coating films formed by the multi coating films forming method, not only it is excellent in the close adhesion of the coating film, corrosion resistance, weather resistance and vibration proofness, but also it is improved in a noise characteristic caused by the friction material as a source of vibration. [0014] Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a schematic view showing a cross sectional layer constitution of a friction member (brake pad). DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS [0016] Exemplary embodiments of the invention will be described with reference to the accompanying drawings. In the exemplary embodiments, a work to be coated with multi layers of coating films and a method of forming multi layers of coating films on a work to be coated of the present invention is applied to a friction member for a brake apparatus, as example in order to explain the present invention. [0017] In the drawing for explaining the exemplary embodiments and examples, constituent factors having identical functions are described with reference to identical reference numerals. [0018] Production of a friction material for use in brakes is generally conducted by way of each of the steps of blending, stirring, preliminarily molding a starting material of a friction member at a normal temperature, thermal forming, thermal treatment and finishing such as grinding. [0019] At first, each of the steps is to be described for an illustrated example of a friction pad for a disk brake as a friction member 1. FIG. 1 is across sectional view of a friction member 1 in which a friction material 4 is integrated by press molding by way of an adhesive 3 to a pressure plate 2 coated with a primer 5 (hereinafter referred to as "P/P") P/P is fabricated by each of the steps of sheet metal pressing, degreasing treatment, primer treatment and P/P preheating as the main step. In the steel sheet metal pressing step, a previously selected P/P raw material is molded into P/P of a predetermined shape by pressing or the like. In the degreasing step, oils and fats deposited to P/P upon pressing are removed by using a detergent. In the primer treating step, a resin primer is spray coated over the entire surface of degreased P/P, dried, heated at 180 to 200.degree. C. for about one hour and the primer is hardened to form a primer layer. For the primer 5, usual primers can be used and include, for example, vinyl/phenol resin (polyvinyl acetal, polyvinyl formal, polyvinyl butyral, and copolyamide as vinyl elastomer), nitrile rubber/phenol resin, silane type resin (for example, .gamma.-aminopropyltriethoxy silane), and urethane type primer. [0020] On the other hand, the preliminary molding of the friction material 4 includes metering, blending, stirring, and preliminary molding of the starting materials as the main step. Each of the steps described above can be in accordance with the existent production technique for the friction material. For example, a starting material is prepared by blending reinforcing fibers such as heat resistant organic fibers, inorganic fibers, and metal fibers with a powdery starting materials such as inorganic fillers, a friction controlling material, solid lubricant and thermosetting resin binder each at a predetermined ratio and sufficiently homogenizing them by mixing and stirring. In the foregoings, the reinforcing fibers include, for example, organic fibers such as aromatic polyamide fibers, flame resistant acrylic fibers, metal fibers such as copper fibers and steel fibers, and inorganic fibers such as potassium titanate fibers and Al.sub.2O.sub.3--SiO ceramic fibers. The inorganic filler includes, for example, inorganic particles such as barium sulfate and calciumcarbonate, and flaky inorganic materials such as vermiculite or mica. The thermosetting resin binder includes and, for example, phenol resins (including straight phenol resin, various kinds of modified phenol resins with rubber), melamine resin, epoxy resin, and polyimide resin. Further, the friction controlling material includes, for example, inorganic friction control materials such as alumina, silica, magnesia, zirconia, and chromiumoxide, organic friction controlling materials such as synthetic rubber and cashew resin. The solid lubricant includes, for example, graphite or molybdenum disulfide. For the composition of the friction material, various ratio can be adopted for the composition. That is, the materials may be used alone or two or more of them may be blended in combination in accordance with friction characteristics required for products, for example, friction coefficient, wear resistance, vibration characteristic and noise characteristic. Continue reading about Work with multi layers coating films and method of forming multi layers coating films... Full patent description for Work with multi layers coating films and method of forming multi layers coating films Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Work with multi layers coating films and method of forming multi layers coating films patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Work with multi layers coating films and method of forming multi layers coating films or other areas of interest. ### Previous Patent Application: Photocuring composition and plasma display panel produced by using the same Next Patent Application: Curable alkanolamine-containing epoxy powder coating composition Industry Class: Stock material or miscellaneous articles ### FreshPatents.com Support Thank you for viewing the Work with multi layers coating films and method of forming multi layers coating films patent info. IP-related news and info Results in 0.13663 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m 174 |
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